Composite bioabsorbable materials and surgical articles made therefrom

Abstract

The present invention relates to composite materials having a core portion formed from a first bioabsorbable material and at least one shell portion of a second bioabsorbable material joined to the core portion. The first and second bioabsorbable materials have different rates of bioabsorption. In a preferred embodiment, the core portion is coextruded with the shell portion to form a composite filament or sheet. The materials of the present invention may be used as sutures or formed into medical devices or surgical articles for implantation within a living organism.

What is claimed is: 
     
       1. A bioabsorbable filament implantable within a living organism comprising: a core portion formed from a first bioabsorbable material;   a shell portion joined to said core portion formed from a second bioabsorbable material;   wherein said first bioabsorbable material has a greater rate of bioabsorption than said second bioabsorbable material, and   wherein said bioabsorbable filament is formed by coextruding said core portion and said shell portion.   
     
     
       2. A bioabsorbable filament as recited in claim 1 wherein said first and second bioabsorbable materials are selected from polymers, copolymers, block copolymers, and mixtures and blends of polymers, copolymers, and block copolymers of glycolide, glycolic acid, lactide, lactic acid, caprolactone, dioxanone, trimethylene carbonate, dimethyl trimethylene carbonate, 1,3 dioxane-2-one, and 1,4 dioxane-2-one. 
     
     
       3. A bioabsorbable filament as recited in claim 1 wherein said first bioabsorbable material comprises a glycolide-containing polymer and said second bioabsorbable material comprises polydioxanone. 
     
     
       4. A bioabsorbable filament as recited in claim 1 wherein said first bioabsorbable material comprises polydioxanone and said second bioabsorable material comprises polycaprolactone. 
     
     
       5. A bioabsorbable filament as recited in claim 1 wherein said shell portion is coextensive with said core portion. 
     
     
       6. A woven prosthetic device made from the composite filament of claim 1. 
     
     
       7. A non-woven prosthetic device made from the composite filament of claim 1. 
     
     
       8. A bioabsorbable filament as recited in claim 1 wherein said shell portion comprises a first shell portion formed from said second bioabsorbable material and a second shell portion formed form a third bioabsorbable material, said second and third bioabsorbable material having different rates of bioabsorption. 
     
     
       9. A bioabsorbable filament as recited in claim 1 further comprising a coating formed over said shell portion. 
     
     
       10. A suture formed from the bioabsorbable filament of claim 1. 
     
     
       11. A bioabsorbable filament implantable within a living organism comprising: a core portion formed from a first bioabsorbable material;   a shell portion joined to said core portion formed from a second bioabsorbable material, the second bioabsorbable material having a rate of bioabsorption different from the rate of bioabsorption of the first bioabsorbable material;   wherein said bioabsorbable filament is formed by coextruding said core portion and said shell portion.   
     
     
       12. A bioabsorbable filament as recited in claim 1 wherein said second bioabsorbable material has a greater rate of bioabsorption than said first bioabsorbable material. 
     
     
       13. A woven prosthetic device made from the composite filament of claim 11. 
     
     
       14. A non-woven prosthetic device made from the composite filament of claim 11. 
     
     
       15. A suture formed from the bioabsorbable filament of claim 11.